Peter Appsis the executive director of PS21 and a veteran reporter. He tweets @pete_apps

Three years after the Obama administration announced its “pivot to Asia,” American allies in the region are looking somewhat unconvinced.

While no one disputes that managing China and its multiple neighborhood conflicts remains on Washington’s radar, this effort is often overshadowed by other priorities. In particular, the Middle East and confrontation with Russia — both historic preoccupations that had been expected to subside — keep on emerging at the top of the agenda.

The result is relatively simple. Those countries in Asia most worried by China — Japan, India, the Philippines, Vietnam, Australia and others — are increasingly banding together. They worry they may need to be capable of taking matters into their own hands regardless of what the United States might do.

It’s a phenomenon that manifests itself in multiple different ways. Japan and Australia, for example, may collaborate on a new submarine — including sharing highly classified information. In another sign of new regional alliances forming, India has also invited Japan to take part in its “Malabar” naval war games, designed to showcase India’s naval strength in the Indian Ocean.

After Congress blocked President Barack Obama’s Trans-Pacific Partnership trade deal last month, Singapore’s foreign minister told an audience in Washington that the United States was losing its levers of power in the region.

“The choice is a very stark one,” K. Shanmugam said. “Do you want to be part of the region or do you want to be out of the region?”

The deal passed through Congress soon thereafter.

This is not, whatever critics might say, a world without American leadership. It’s more complicated than that — and America is still an important player.

Washington remains the dominant naval power in Asia even against the backdrop of a growing Chinese fleet. And, crucially, it remains without doubt the single-most important partner for each of its regional allies. Even India, historically dedicated to a “non-aligned” position between East and West, has moved much closer to Washington under Prime Minister Narendra Modi. The Malabar military exercises will also involve the United States.

But it is a world where American leadership is pulled in multiple different directions. The United States must deter both Russia and China from attacking its treaty allies — and so sparking a major war — without simultaneously antagonizing them so much that conflict becomes more likely.

Much of Washington’s military and diplomatic focus, meanwhile, remains on the Middle East: the war against Islamic State, the Iran deal and — for Secretary of State John Kerry in particular — the Israeli Palestinian peace process. These distractions are understandable and in many cases unavoidable — although Kerry in particular has a reputation for being not interested in Asia, which some analysts say has been harmful to relations. China, in contrast, remains resolutely focused on its immediate neighborhood.

And at the same time that America’s military dominance is being challenged by other powers, its own spending is beginning to slip.

Asian countries, by contrast, have been on a major spending spree in recent years. Australia grew its defense budget by 6.7 percent in 2014 alone. South Korea and India saw their spending rise 2.3 and 1.8 percent. In January, Japan announced its largest defense budget since World War Two.

How closely these countries will coordinate their defenses — and how tightly the United States is wrapped into that system — remains to be seen. For China — whose 9.7 percent spending increase last year tops any other country in Asia — the greatest worry is that its potential enemies coalesce into a formal NATO-style structure, although this seems unlikely for now. More ad hoc relations, for example, between India and Vietnam or the Philippines and Japan, are growing by the year.

In Washington, some current and former officials, as well as analysts, worry that the United States may simply lose its ability to shape events in the region — while still risking being dragged into a conflict if one, or more, of its allies end up fighting China.

While few believe anyone in Beijing or elsewhere would wish for such a conflict, China has clearly signaled its intention to boost its clout in its immediate neighborhood. China’s various construction projects on disputed South China Sea islands — as well as an increasingly assertive posture by its naval and air forces in the region — will likely continue and intensify.

This trend goes well beyond China’s immediate neighborhood. From Sri Lanka to Afghanistan, analysts now talk of a “new great game” in South Asia as China jostles against India, in particular.

The Middle East, paradoxically, may provide some indication of how this could go. For all Washington’s ongoing focus on the region, many of its allies — particularly the Gulf States and Saudi Arabia — increasingly question its commitment there. They, too, are ramping up their defense spending: Saudi Arabia’s 17 percent increase last year was the greatest hike worldwide.

As a result, the United States has increasingly struggled to influence and control its allies in the region. The Saudi-led campaign against Iran-linked Houthi militia in Yemen, for example, seems out the West’s realm of influence. The same goes for the multiple regional powers backing different groups in Libya.

Asia’s confrontations will, for now, almost certainly remain bloodless and largely contained offshore and to the economic, business and cyberspace spheres.

But whatever Washington does, its grasp on the region — like so many others — is slowly faltering. It may or may not be an Asian century — but in Asia at least, it will be regional powers that increasingly call the shots.